Ninebark (Physocarpus spp.) is an extremely versatile plant. Its fast-growing habit and appealing winter bark make ninebark shrubs garden favorites. The traditional ninebark foliage color is a deep purple, but new foliage colors include gold and amber. Some varieties even fade from one color to another as they age.

Ninebark flowers are almost an afterthought. While they look nice, especially on varieties with dark foliage, the white and pink blooms don't last long. In the winter, the bark is what shines. As the bark of the older stems ages, it peels back in layers, creating an exfoliation effect.

Recent innovations have focused on shrinking the plant size to better adapt to a home garden setting. In smaller varieties, habits have also changed to be more upright.

Where to Plant Ninebark

Ninebark shrubs can be planted alone as specimen plants or used as foundation plants in beds and as hedges. They are also useful for erosion control on banks. Choose a full-sun or part-sun location with well-drained, fertile soil in USDA hardiness zones 3–7.

How and When to Plant Ninebark

Set out plants from a garden center any time from spring to early autumn. Dig a hole twice as wide as the nursery container and slightly deeper. Loosen the soil in the bottom of the hole and add compost. Position the plant so the top of the root ball is level with the soil line. Backfill the hole and press down on the soil to remove air pockets. Water thoroughly. If you plant multiple shrubs, space them 4 to 6 feet apart.

Ninebark Care Tips

This versatile plant is a standout in the home garden as long as its basic needs are met.

Light

Ninebark is at its best in full sun or part sun. It will grow in shade, but it flowers more profusely with more light.

Soil and Water

Ninebark tolerates many soil conditions, including clay and rocky soils, but prefers moist, well-draining soil with a neutral or slightly acidic pH.

When the plants are young, water them a couple of times a week during the hottest part of the summer. Mature plants don't need much watering as long as the soil is moist. They don't respond well to overwatering and are drought-tolerant.

Temperature and Humidity

Ninebark tolerates a wide range of environmental factors, but hot areas with high humidity increase the chance of the plant developing a fungal infection.

Fertilizer

An annual application of fertilizer in spring is sufficient for ninebark plants. Use a slow-release, balanced granular fertilizer, such as a 10-10-10. For the amount to use, follow product label directions. Don't fertilize the plant in late fall or winter when it is dormant.

Pruning

Ninebarks are amenable to severe pruning. Prune them in early spring by removing the largest canes all the way to the ground. During the growing season, remove any damaged stems or thin out crowded areas of the plant. In winter, prune the plant while it is dormant for size management.

Pests and Problems

The biggest problem that ninebarks encounter is powdery mildew. Fortunately, it doesn't do long-term harm. Thinning out older stems can increase air circulation and prevent mildew. The newer ninebark introductions are more resistant to powdery mildew.

Aphids can be troublesome, but they can be treated with a blast of water from a garden hose, insecticidal soap, or neem oil.

How to Propagate Ninebark

Propagate ninebark by root suckers during its winter dormant period or by stem cuttings during the growing season.

Propagate with root suckers:

• Move the soil away from the base of the dormant plant to locate the root that connects to the sucker.
• Use a sharp knife to cut the root.
• Use a shovel to lift the roots of the sucker and shake off most of the soil.
• Dig a hole twice as deep as the root ball of the sucker and three times as wide. Break up the soil with a shovel and refill the hole halfway.
• Position the roots on top and cover them with soil, making sure the sucker is not planted any deeper than it was initially.
• Tamp down the soil lightly and water well.

Propagate with stem cuttings:

Take stem cuttings during the growing season by harvesting 4- to 6-inch cuttings from the current season's growth in late summer. Although rooting hormone is not necessary for ninebark plants, you may use it. Insert the cuttings into a medium of peat and sand. Place them outside in a shady area. The cuttings should root in four to six weeks.

Types of Ninebark

'Summer Wine' Ninebark

Physocarpus 'Summer Wine' is a compact purple-leaf selection that grows 5-6 feet tall and wide. Zones 3-7

'Dart's Gold' Ninebark

Physocarpus 'Dart's Gold' offers bright golden-yellow foliage and white flowers in early summer. It grows 6 feet tall and 8 feet wide. Zones 3-7.

'Donna May' Ninebark

Physocarpus opulifolius 'Donna May' is an outstanding dwarf selection that displays rich burgundy-purple leaves with white flowers in early summer. It grows 4 feet tall and wide. Zones 3-7

'Coppertina' Ninebark

Physocarpus 'Coppertina' shows off coppery-purple new growth that matures to purple-red. It grows 8 feet tall and 10 feet wide. Zones 3-7

'Center Glow' Ninebark

Physocarpus 'Center Glow' bears purple foliage with a golden-yellow center when young. It grows 8 feet tall and wide. Zones 3-7

'Diablo' Ninebark

Physocarpus 'Diabolo' features rich burgundy-purple foliage and white flowers. It grows 10 feet tall and wide. Zones 3-7